The winner of the walk-on role competition for Harry Potter and the Prisoner of Azkaban describes his experience of visiting the set and of filming his scene with the stars of the movie.
The scene was: All the students are in the Great Hall studying homework or just entertaining themselves (this is just shortly after Tom "Malfoy" is attacked by the hippogriff in Hagrid's class). I was sitting just a few seats down from Daniel and Emma, playing a game against another Gryffindor, 1st year.
We met Hedwig, Scabbers, Crookshanks, the cat Professor McGonagall changes into, and we got to pet Fang. He sure slobbers a lot but was so playful. I got some great pictures of him.